In general, a pushbutton tuner is required to have a rotary fine tuning mechanism operable by manual handling as well as a tuning mechanism operable by push buttons. As known, this fine tuning mechanism is mounted on left or right side of the pushbutton tuner housing depending upon the position in a car where the mechanism is mounted. However, the design of the pushbutton tuner such as arrangement of a circuit board for the fine tuning mechanism and other components should be greatly changed depending upon which side the mechanism is mounted on. Accordingly, a manufacturing line for the pushbutton tuners should be changed depending upon the types of the pushbutton tuners as mentioned above and the manufacturing line adapted for either one of the types of the pushbutton tuner cannot be used for another type of pushbutton tuner. Thus, the manufacturing line is selected according to a manufacturing schedule of desired type of pushbutton tuners.